Zhu Shu, Jiang Fengtao, Han Yu, Xiang Nan, Ni Zhonghua
School of Mechanical Engineering, and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, 211189, China.
Analyst. 2020 Nov 9;145(22):7103-7124. doi: 10.1039/d0an01148g.
Circulating tumor cells (CTCs) have been widely considered as promising novel biomarkers for molecular research and clinical diagnosis of cancer. However, the sorting of CTCs is very challenging due to the rarity of CTCs in blood and the morphological similarity to blood cells. Although affinity-based CTC sorting methods could capture CTCs using specific biochemical markers, there are limitations such as the loss of cell viability after labeling and a requirement for expensive biochemical marker reagents. Emerging label-free CTC sorting methods rely on the physical properties of cells and can potentially overcome the aforementioned limitations. In this review, we highlight recent advances in label-free CTC sorting methods, with emphasis on device structures and performances. Specifically, we present a detailed discussion on label-free CTC sorting methods, including passive ones that depend on the channel structure or specific fluidic effects and active ones that use external force fields, as well as provide an overview of the principles, advantages, limitations, and applications of state-of-art label-free CTC sorting devices. Finally, we provide a future perspective of microfluidics for label-free CTC sorting and hope to inspire readers to develop new devices for applications in clinical cancer diagnoses and research.
循环肿瘤细胞（CTCs）已被广泛认为是癌症分子研究和临床诊断中很有前景的新型生物标志物。然而，由于血液中CTCs的稀缺性以及与血细胞在形态上的相似性，CTCs的分选极具挑战性。尽管基于亲和力的CTCs分选方法可以利用特定的生化标志物捕获CTCs，但存在诸如标记后细胞活力丧失以及需要昂贵的生化标志物试剂等局限性。新兴的无标记CTCs分选方法依赖于细胞的物理特性，并且有可能克服上述局限性。在这篇综述中，我们重点介绍无标记CTCs分选方法的最新进展，重点关注设备结构和性能。具体而言，我们对无标记CTCs分选方法进行了详细讨论，包括依赖通道结构或特定流体效应的被动分选方法以及使用外力场的主动分选方法，并概述了当前最先进的无标记CTCs分选设备的原理、优点、局限性和应用。最后，我们对用于无标记CTCs分选的微流体技术给出了未来展望，并希望激发读者开发新设备以应用于临床癌症诊断和研究。
